A Cmos Image Sensor Using Variable Reference Time Domain Encoding

• doi: 10.1109/ISCAS.2007.377943
• title: A CMOS Image Sensor using Variable Reference Time Domain Encoding
• publisher: IEEE
• isbn: 1-4244-0921-7
• issn: 2158-1525
• partnum: 07CH37868
• rank: 553
• access_type: LOCKED
• content_type: Conferences
• abstract: In this paper, a Variable Reference Time Domain Encoding CMOS image sensor is presented. The time domain encoding vision sensor is known to suffer from slow conversion time, especially at low level of illumination. This is due to limited photocurrent generated to discharge the photodiode junction voltage to the reference voltage. A variable referencing scheme is proposed so that the reference voltage will be modulated and bounded by a specified deadline. The pixel consists of a photodiode, an analogue comparator, an 8-bit SRAM, a SR latch, and occupies an area of 32μm × 35μm, with a fill-factor of 12.6 % using a 0.35μm CMOS process. Simulation results show that signal conversion can be achieved by using pre-defined threshold voltages. By using four levels of reference voltage and ⅒ of the original conversion time required by the original time domain encoding, over 70% reduction in total integration time can be achieved.
• article_number: 4253159
• pdf_url: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4253159
• html_url: https://ieeexplore.ieee.org/document/4253159/
• abstract_url: https://ieeexplore.ieee.org/document/4253159/
• publication_title: 2007 IEEE International Symposium on Circuits and Systems (ISCAS)
• conference_location: New Orleans, LA, USA
• conference_dates: 27-30 May 2007
• publication_number: 4252534
• is_number: 4252535
• publication_year: 2007
• publication_date: 27-30 May 2007
• start_page: 2399
• end_page: 2402
• citing_paper_count: 4
• citing_patent_count: 0
• download_count: 237
• insert_date: 20070625
• index_terms:
  • ieee_terms:
    • CMOS image sensors
    • Image coding
    • Voltage
    • Encoding
    • Photodiodes
    • Image converters
    • Lighting
    • Photoconductivity
    • Random access memory
    • Strontium
  • dynamic_index_terms:
    • Image Sensor
    • Camera Sensor
    • Variable Domain
    • Time-domain Encoding
    • Simulation Results
    • Reduction In Time
    • Integration Time
    • Photodiode
    • Threshold Voltage
    • Original Time
    • Voltage Levels
    • Setup Time
    • Conversion Time
    • Original Domain
    • Quantization Error
    • Amount Of Error
    • Supply Voltage
    • High Dynamic Range
    • Control Circuit
    • Junction Capacitance
    • Gray Code
    • Grey Number
    • Standard CMOS
• isbn_formats:
  • format: CD, value: 1-4244-0921-7, isbnType: Historical
  • format: Print ISBN, value: 1-4244-0920-9, isbnType: Historical
• authors:
  • Author Name: M. K. Law
    Affiliation: Department of Electrical and Computer Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
    Author URL: https://ieeexplore.ieee.org/author/37072476800
    ID: 37072476800
    Order: 1
    Author Affiliations:
    • Department of Electrical and Computer Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
  • Author Name: A. Bermak
    Affiliation: Department of Electrical and Computer Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
    Author URL: https://ieeexplore.ieee.org/author/37275353200
    ID: 37275353200
    Order: 2
    Author Affiliations:
    • Department of Electrical and Computer Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China

Image Sensor

• sensor_type: CMOS
• resolution: 128x128
• dynamic_range: High
• pixel_size: 32µm x 35µm
• dark_current: Not specified

Optical Data

• focal_length: Not specified
• aperture: Not specified
• field_of_view: Not specified
• distortion: Not specified

Performance Metrics

Applications & Benefits

• cell_imaging: Potential applications include smartphones, medical devices, and automotive systems.
• benefits: Over 70% reduction in total integration time with variable reference time domain encoding.

Supporting Organizations

• supported_by: Research Grant Council of HK SAR, China (Projects No 610405 and HKUST6148/03E)

Manuscript Details

• publication_date: 27-30 May 2007

Relevancy Score

• score: 9
• missing_fields:
  • quantum_efficiency
  • readout_speed
  • noise_sources
  • microlenses
  • on_chip_colour_filters
  • global_shutters
  • rolling_shutters
  • backside_illumination

Processed JSON Filename

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